A new scientific study has revealed that fossil leaves discovered in Nagaland have provided crucial evidence linking the formation of Antarctic ice around 34 million years ago with the early evolution of the Indian monsoon system, PIB report stated.
The well-preserved fossil leaves, unearthed from the Laisong Formation in Nagaland, indicated that the region once had a warm and wet climate. This prompted researchers from the Birbal Sahni Institute of Palaeosciences, Lucknow, and Wadia Institute of Himalayan Geology, Dehradun—both under the Department of Science and Technology (DST)—to carry out detailed climate reconstruction.
The results showed very high rainfall and temperatures, leading scientists to trace the cause to a global shift that coincided with the first massive ice formations in Antarctica. According to the study, published in Palaeogeography, Palaeoclimatology, Palaeoecology, the growth of Antarctic ice reshaped global wind and rainfall patterns by shifting the Intertropical Convergence Zone (ITCZ)—a major tropical rain belt—northwards. This shift brought intense monsoonal rains to Northeast India, enabling dense forests to thrive.
Using the CLAMP (Climate Leaf Analysis Multivariate Program) technique, scientists reconstructed past climates by analysing the size, shape, and structure of the fossilized leaves. The findings revealed that Nagaland once experienced much wetter and warmer conditions compared to the present, coinciding with the global timing of Antarctic glaciation.
Experts said the study not only sheds light on Earth’s deep past but also carries implications for the future. They warned that as modern climate change accelerates Antarctic ice melt, the ITCZ could shift again, disrupting rainfall patterns across the tropics. For India, this may bring profound changes in the monsoon—the lifeline of agriculture, water supply, and millions of livelihoods.
The study underlined that Earth’s climate operates as a global web, where shifts in one region—such as Antarctica—can have far-reaching impacts on distant ecosystems, including the forests of Nagaland.
